Multimedia Broadcast/Multicast Service (MBMS) is a point-to-multipoint service in which data is transmitted from a single source entity to multiple recipients. Transmitting the same data to multiple recipients allows network resources to be shared.
Evolved Multimedia Broadcast/Multicast Service (eMBMS) is a broadcasting service offered via Evolved Packet Systems, including the evolved UMTS Terrestrial Radio Access Network (E-UTRAN) of the 3rd Generation Partnership Project's (3GPP's) Long Term Evolution (LTE) architecture.
A typical application for eMBMS is to deliver video content relating to a sporting game or event to a large number of mobile phones owned by users gathered in a stadium. An eMBMS system can use a MBMS streaming delivery method or MBMS download delivery method to deliver live television content to such terminals. The MBMS streaming delivery method relates to delivering continuous multimedia data over MBMS bearers, while the MBMS download delivery method uses the FLUTE (File Delivery over Unidirectional Transport) protocol when delivering content over MBMS bearers. Applying HTTP Live Streaming (HLS) or Dynamic Adaptive Streaming over HTTP (DASH), media segments can be delivered as files over a MBMS download to offer the most popular and demanding service, Live TV.
Another typical application is the distribution of popular updates, such as an Android™ update for example, to many users. An eMBMS system can use the MBMS download delivery method (UDP/FLUTE) as the protocol to deliver popular files such as an Android™ update, or indeed other files such as a YouTube™ clip preloading, or major news events.
In eMBMS, the user services are described in a data model as shown in FIG. 1, which is defined in the technical specification relating to 3GPP TS 26.346. FIG. 1 illustrates a simple data model relation between description instances using a Unified Modelling Language (UML) for a single User Service Bundle Description 101, where “N” indicates that there can be any number in each instance.
This data model comprises fragments of metadata which are delivered to many user equipments in a suitable manner. A metadata fragment can be considered as a single uniquely identifiable block of metadata.
The User Service Bundle Description fragment 101 relates to the one-to-group user services. It may contain one or more User Service Description (USD) instances 103. It may also refer to a single FEC Repair Stream Description 105. The User Service Description instance 103 contains one or more Delivery Method description 107, which is used to describe how the service is delivered to a user equipment (UE) node. The Delivery Method description 107 refers to a Session Description instance 109, which describes the delivery related parameters. An Associated Delivery Procedure Description 111 may also be referenced by a Delivery Method description 107 to provide the complementary delivery method for the service (for example file repair in eMBMS). The Delivery Method description 107 may also reference a Security Description 113 to provide service protection information.
In the event that Dynamic Adaptive Streaming over HTTP (DASH) formatted contents are to be delivered in eMBMS, the User Service Description fragment 103 will contain a Media Presentation Description instance 115. The Media Presentation Description instance 115 will reference to a Media Presentation Description (MPD) fragment 117, which also may refer to one or more Initialisation Segment Description (ISD) fragments 119.
The User Service Description instance 103 may also include one Schedule instance 121, which refers to one Schedule Description fragment 123, which describes the scheduled delivery periods.
Interactivity is one of the most attractive features in Mobile TV services. Typical applications are interactivity messages, commercials, advertisements, text tickers, voting, chat, and so on. For example, during a live TV show that is being watched by many users, a dialog can be popped up towards end users, asking the users to vote for a winner. Another typical example can be in relation to a user watching a video clip, whereby a rolling text is presented from time to time, to provide advertisement information towards the end users. In such examples the dialog or the rolling text itself can be considered as interactivity media.
The interactivity media therefore contains the interactivity information which is to be presented towards end users by their respective UEs. The interactivity media can take several forms, for example a JPEG image to be displayed as an advertisement banner, or an HTML/XHTML page to be displayed as a text ticker for news or weather information. As another example the interactivity media could be a SVG dialog requesting an end user to vote. Depending on the capability of the UEs being used by end users, the format of the interactivity media can vary.
A disadvantage of existing systems is that, while it is possible for a UE to receive interactivity media from a broadcasting bearer, as well as the linear TV channel or video clip, a UE is not able to perform any other functions, for example associating the interactivity media with any specific linear TV channel or a video clip. A UE is also not aware of when the interactivity media should be presented towards end users. It is therefore difficult for a UE to offer an interactivity function for a Mobile TV service, unless it implements some proprietary extension together with a Mobile TV server, which is not included in eMBMS standards defined by 3GPP.